Duration Of Thawing Research Articles

Zonality in the dynamics of the seasonally thawed layer in the landscapes of Yakutia

Abstract The article presents a pattern of zonation that may be discerned in terms of the behavior of the seasonally thawed layer in Yakutia. What emerges is basically a latitudinal zonation within which a tundra zone, a northern taiga subzone, and a middle taiga subzone may be identified within Yakutia. In general the short‐term variability in the thickness of the seasonally thawed layer, as well as the length of the thaw period, increases from north to south. Local variations in such factors as moisture conditions, accumulation of organic material, aspect, etc., will inevitably cause variations in the length of period of thaw, depth of thaw, and the temporal patterns of the onset of thaw, duration of thaw, and duration and direction of refreezing, within the general latitudinal zonation.

Feasibility study of permafrost thawing regime by electric heaters

The distance between heaters and their capacity, or the duration of thawing, are basic parameters assigned during design for a given depth of thaw and dimensions of the thawed sectiQn. The minimum complete cost of work involving preliminary thawing of permafrost in the bed of a specific building or structure, which is summed from the costs for drilling holes for the heaters Cd, the preparation, installation, and connection of the heaters Cp, the cost of electric energy Ce, and the conditional cost for the duration of thawing CT, is a condition that ensures the most rational use of energy, materials, equipment, and labor outlays.

Free amino acid content of lymphocytes nd granulocytes compared.

For extracting free amino acids from human leukocytes, we find that disruption of the cells by ultrasonication is more reliable than freezing and thawing. The amount of free amino acids extracted by the latter method depends on the temperature and duration of thawing. We extracted free amino acids from leukocytes of healthy men by ultrasonication and compared their concentrations in lymphocytes and granulocytes. The amino acid content of granulocytes significantly (p less than 0.001) exceeded that of lymphocytes. Of the amino acids extracted from granulocytes, 76% was taurine; for lymphocytes taurine, aspartic acid, and glutamic acid were predominant, respectively composing 44%, 17%, and 26% of the total. Taurine is proposed as an index of cell disruption.

Duration of steam thawing of Frozen ground

Duration of steam thawing of Frozen ground

Cryonecrosis of normal and tumor-bearing rat liver potentiated by inflow occlusion.

Cryosurgery involving large portions of rat liver with and without inflow occlusion was generally well tolerated. Tumors were successfully eradicated in 8 of 10 (80%) animals with rapidly enlarging hepatic tumor implants. Necrosis of liver parenchyma was localized and reproducible histologically. No hemorrhage or bile leakage was encountered in the target area or in adjacent untreated liver. SGOT and SGPT values rose transiently after treatment and reflected directly the extent of cryonecrosis. The magnitude of the cold insult and, hence, the volume of histologic cryonecrosis were not predictable by the size of the iceball at the time of freezing, but were affected by the rate and depth of freezing and the duration of thawing. Rapid freezing and slow thawing are maximally lethal. The cold insult was increased by the addition of two and three freezes (repetitive freezing) and was enhanced by ischemia as indicated by regional temperature measurements using thermocouples.

Effect of Duration and Type of Chilling and Thawing on Tenderness of Frozen Turkeys

INTRODUCTIONTHE poultry industry is ever alert to possibilities of increasing processing efficiency and product quality through modifications of chilling procedures and related processes. Chilling methods providing mechanical agitation of the carcasses result in markedly greater chilling rates than conventional chilling in tanks of ice slush, and hence are highly desirable if optimum quality, including adequate tenderization, can be assured under the modified conditions. A previous publication from this laboratory (Klose et al., 1960) reviewed the literature and reported laboratory scale chilling studies on chicken broilers and small fryer-roaster turkeys, cooked from the frozen state. These studies demonstrated that in rapid ice slush chilling accomplished with laboratory scale, mechanical tumbling, the minimum required tenderizing period is much in excess of that time required for adequate chilling of the carcass; that is, rapid chilling in itself does not appear to have any important effect on rate of tenderization. Kahlenberg et al.…